Seal for lifter roof storage tanks



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SEAL FOR LINER ROOF STORAGE TANKS Fled Jan. 9, 1946 2 Sheets-Sheet l C 22 'i949 H. c. BOARDMAN ETAL SEAL FOR LIFTER ROOF STORAGE TANKS Patented Mai".y 22, 1949 SEAL FOR LIFTER ROOF STORAGE TANKS Harry C. Boardman, Fred L. Goldsby, and Clifford M. Orr, Chicago, Ill., assignors to Chicago Bridge & Iron Company, a corporation of Illinois Application January 9, 1946, Serial No. 639,946

Il Claims. (Cl. 48-176) This invention relates to a lifter roof storage tank for the storage of gases or liquids and gases, and relates particularly to a seal for sealing the area between the roof and the body portion of the tank.

Lifter roof storage tanks are used for the storage of gases or of mixtures of liquids and gas. The roof is arranged to rise and fall as the stored gas is increased and decreased. Thus the tank operates at substantially constant pressure during the travel of the roof.

In tanks of this type it is necessary to provide a ilexible sealing means for sealing the area between the roof and the body portion of the tank in order to prevent the escape of the contents of the tank. This sealing means should be flexible so that it can readily adjust itself to the different positions of the roof, and must be impervious to gas, so as to prevent escape of the contents of the tank. We have invented an improved seal for a lifter roof storage tank that provides a positive sealing action and that readily adjusts itself to all positions of the roof. The seal is quite simple in construction and will require very little attention and upkeep. The seal comprises, broadly, a depending rim on the lifter roof, a iiexible sealing member attached to the top edge of the tank shell and to the depending rim, and spaced substantially horizontal reinforcements at the iiexible sealing member dividing it into substantially horizontal sections.

The invention will be described as related to the embodiments show'n in the accompanying drawings. Of the drawings Fig. 1 is a fragmentary plan view of one embodiment of the invention with portions broken away; Fig. 2 is a fragmentary vertical section through the tank of Fig. 1; Fig. 3 is a view similar to Fig. 1 with the roof in its lowest position; Fig. 4 is a fragmentary vertical section through an alternate type of tank embodying the invention with the roof in fully expanded position; Fig. 5 is a view similar to Fig. 4, with the roof in its lowest position; Fig. 6 is a fragmentary vertical section showing a second embodiment of the invention with the roof in fully expanded position; and Fig. 7 is a view similar to Fig. 6 with the roof in its lowest position.

In the embodiment shown in Figs. 1, 2 and 3 the storage tank comprises a shell III and a lifter roof II with the edge of the roof extending beyond the shell I0. The liiter roof II is provided with a downwardly extending rim I2 at the edge of the roof having a diameter greater than the diameter of the shell I0. Extending 2 l between the top of theshell I0 and the depending rim I2 is a flexiblesealing member I3 having the shape of a irustrum of a cone. Attached to the sealing member I3 are spaced horizontal circular rods I4 dividing the sealing member into sections. The inner edge of the sealing member I3 is attached to the top edge of the shell Ill as by a plurality of spaced bolts I5. The outer edge of the sealing member is attached to the depending rim I2 by a second set of spaced bolts I6. The depending rim I2 serves to hold the outer edge of the sealing member I3 and also serves as a weather skirt to protect the seal from wind, rain, andthe like. When the roof is in its lowest position, as shown in Fig. 3, the roof II rests on the top edge of the shell I0.

In the embodiment shown in Figs. 4 and 5 the depending rim l2 has a diameter smaller than the diameter of the shell I0. A separate weather skirt I'l is provided at the edge of the roof II with the weather skirt having a diameter larger than that of the shell I0.

In the embodiment shown in Figs. 6 and 7 the depending rim I2 has a diameter smaller than that of the shell I0, while the diameter of the weather skirt I'l is greater than that of the shell. The sealing means in this embodiment comprises a series of flexible sealing members I8, I9, and 20 with the inner sealing member I8 having one edge attached to the bottom of the depending rim I2 by means of bolts 2l, and its other edge attached to the top of a cylinder 22 by bolts 23. The middle sealing member I9 has one edge attached to the bottom of the cylinder 22 by means of bolts 24, and its other edge attached to the top of a second cylinder 25 by means of bolts 26. The outer sealing member 20 has one edge attached to the bottom of cylinder 25 by means of bolts and its other edge attached to the top of the shell I0 by means of bolts 28. The cylinders 22 and 25 vary in diameter with the first cylinder 22 being of smaller diameter than the second cylinder 25, and the second cylinder having a diameter smaller than that of the shell III. The ilexible sealing members I8, I9, and 20 have their attached edge portions extending downwardly with the middle por- -tion of each sealing member bowed upwardly by pressure of gas within the tank. There are provided a plurality of spaced brackets 29 around the top of the shell I0 of the tank and extending inwardly. These brackets serve to support the rim I2, rst cylinder 22, and second cylinder 25 when the roof II is in its lowest position, as shown in Fig. 7. The-roof will ordinarily rest on top of the shell I and the cylinders 22 and 25, when the roof is in its lowest position, and the bottom of the rim l2 will be supported by the brackets 29.

The flexible sealing members shown and described herein may be a fabric impregnated with a exible impervious material.

Any of the usual stabilizing and leveling devices may be used on the lifter roof tanks, and any desired means may be employed for illling and emptying the tanks. The usual safety release valves may also be used to release pressure when the roofs have reached their maximum travel.

Having described our invention as related to several embodiments of the invention, it is our intention that the invention be not limited by the details of description unless otherwise specied, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

We claim:

1. In a lifter roof storage tank comprising a tank shell and a lifter roof thereover, a seal comprising a downwardly depending rim on the lifter roof, said rim having a diameter Adiiiering from the diameter of the shell, a llexible sealing member attached to the top edge of the tank shell and to the depending rim, and spaced substantially horizontal annular reinforcements attached to the flexible sealing member dividing it into substantially horizontal annular sections.

2. The seal of claim 1 wherein the horizontal reinforcements have diameters differing progressively from edge to edge of the sealing member.

3. The seal of claim 1 wherein the reinforcements are substantially circular rods.

4. In `a lifter roof storage tank comprising a tank shell and a lifter roof thereover, a seal comprising a depending rim on the lifter roof having a diameter diierent from that of the tank shell, a flexible sealing member attached to the top edge of the tank shell and to the depending rim, said sealing member having substantially the shape of a frustrum of a cone, and spaced substantially horizontal circular reinforcing rods attached to the flexible sealing member with the rods progressively increasing in diameter from the inner to the outer part of the seal.

5. In a lifter roof storage tank comprising a tank shell and a lifter roof thereover, a seal comprising a depending rim on the lifter roof having a diameter smaller than the diameter of the tank shell and substantially concentric thereto, a flexible sealing member attached to the top edge of the tank shell and to the depending rim, said sealing member having substantially the shape of a frustrum of a cone, and spaced substantially horlzontal circular reinforcing rods attached to the flexible sealing member with the rods progressively increasing in, diameter from the inner to the outer part of the seal, said lifter roof restingl on top of the tank shell when the roof is in its lowest position.

6. In a lifter roof storage tank comprising a tank shell and a lifter roof thereover, a seal comprising a depending rim on the lifter roof having a diameter greater than that of the tank shell and substantially concentric thereto, a ilexible sealing member attached to the top edge of the tank shell and to the depending rim, said sealing member having substantially the shape of a frustrum of a cone, and spaced substantially horizontal circular reinforcingT rods attached to the flexible sealing member with the rods progressively increasing in diameter' from the inner to the outer part of the seal, said lifter roof resting on top of the tank shell when the roof is in its lowest position.

7. The seal of claim 6 wherein the depending rim extends below the top edge of the tank shell when the roof is in its highest position.

8. In a lifter roof storage tank comprising a tank shell and a lifter roof thereover, a seal comprising a depending rim on the lifter roof having a diameter diiferent from that of the tank shell, a series of substantially concentric cylinders of gradually increasing diameter from the inner to the outer part of the seal arranged between the depending rim and the tank shell, a series of ilexible sealing members also arranged between the depending rim and the tank shell with an end flexible member attached to the rim, the other end flexible member attached to the tank shell, and the remaining flexible members attached to adjacent cylinders, said two end exible members being also attached to end cylinders and means for supporting the roof in its lowest position.

9. The seal of claim 8 wherein the diameter of all cylinders increases gradually between the rim and the shell and a support is provided on the shell upon which at least some of the cylinders rest when the roof is in substantially its lowest position.

HARRY C. BOARDMAN. FRED L. GOLDSBY. CLIFFORD M. ORR.

No references cited. 

